I have defined the following two Models:

Question.php:

<?php

class Question extends \Eloquent
{
    protected $table = 'questions';
    protected $guarded = ['id'];

    public function answers()

    {

        return $this->hasMany('Answer');

    }
}

Answer.php:

<?php

class Answer extends \Eloquent
{
    protected $table = 'answers';
    protected $guarded = ['id'];

    public function question()
    {
        return $this->belongsTo('Question');
    }
}

And I'm trying to insert data to the Pivot table using this:

$answer = Answer::create([
                        'answer' => $value,
                        'question_id' => $question->id,
                    ]);

$question = Question::find($question->id);
$question->answers()->attach($answer->id);

But I'm getting error that function attach() is undefined. How to solve this?